Stylus battery reported as having 1% charge even though fully charged

Stylus battery reported as having 1% charge even though fully charged

[Sebastian Arnhold]

Dear developers,

when using GNOME 41.1 on Wayland, it reports my stylus battery to be 
stuck at 1% all the time, independent of its actual charging status. 
This is also independent from the stylus I use, as I've tried with two 
different ones.

The device registers as ELAN9008:00 04F3:2DD4 in GNOME settings.

The GNOME developers helped me track the bug down to upower, as upower 
itself shows the charging status to be stuck at 1%. The upower 
developers then closed my bugreport and relayed me here, since they 
believe it's a bug in the kernel itself.

Can you help me fix this?

Thanks in advance,
Sebastian

Re: Stylus battery reported as having 1% charge even though fully charged

[Bastien Nocera]

On Tue, 2022-01-25 at 20:48 +0100, Sebastian Arnhold wrote:
> Dear developers,
> 
> when using GNOME 41.1 on Wayland, it reports my stylus battery to be 
> stuck at 1% all the time, independent of its actual charging status. 
> This is also independent from the stylus I use, as I've tried with
> two 
> different ones.
> 
> The device registers as ELAN9008:00 04F3:2DD4 in GNOME settings.
> 
> The GNOME developers helped me track the bug down to upower, as
> upower 
> itself shows the charging status to be stuck at 1%. The upower 
> developers then closed my bugreport and relayed me here, since they 
> believe it's a bug in the kernel itself.
> 
> Can you help me fix this?

FWIW, you need something like this for your device:
https://www.spinics.net/lists/linux-input/msg71471.html

Stylus battery reported as having 1% charge even though fully charged

[Sebastian Arnhold]

Dear developers,

when using GNOME 42.3 on Wayland on my ASUS ExpertBook B5 Flip, it 
reports my stylus battery to be stuck at 1% all the time, independent of 
its actual charging status. This is also independent from the stylus I 
use, as I've tried with two different ones.

The battery device registers as ELAN9008:00 04F3:2E12 in GNOME energy 
settings.

The GNOME developers helped me track the bug down to upower, as upower 
itself shows the charging status to be stuck at 1%. The upower 
developers then sent me here.

My kernel version is 5.18 on an x86_64 architecture on Fedora 36. My 
upower version is 0.99.19.

Observed behaviour: Kernel reports 1% after pen is switched on and 
touches the touchscreen for the first time. upower reports this to GNOME 
which then throws a "Battery low"-warning message.
Expected behaviour: Kernel reporting the correct charging percentage 
from the pen to upower, or 0% if charging status cannot be determined. 
The latter would be a workaround since 0% seems to be ignored by GNOME.

Can you help me to resolve this bug?

Thanks in advance!
Sebastian


Attachment 1 - Output of upower -d BEFORE pen switched on and touched 
screen:

Device: 
/org/freedesktop/UPower/devices/battery_hid_0018o04F3o2E12x0001_battery
   native-path:          hid-0018:04F3:2E12.0001-battery
   model:                ELAN9008:00 04F3:2E12
   power supply:         no
   updated:              Do 01 Jan 1970 01:00:00 CET (1658223097 seconds 
ago)
   has history:          yes
   has statistics:       yes
   keyboard
     present:             yes
     rechargeable:        yes
     state:               unknown
     warning-level:       none
     percentage:          0%
     icon-name:          'battery-missing-symbolic'


Attachment 2: Output of upower -d AFTER pen switched on and touched 
screen (resulting in "battery low" message in GNOME):

Device: 
/org/freedesktop/UPower/devices/battery_hid_0018o04F3o2E12x0001_battery
   native-path:          hid-0018:04F3:2E12.0001-battery
   model:                ELAN9008:00 04F3:2E12
   power supply:         no
   updated:              Di 19 Jul 2022 11:33:19 CEST (5 seconds ago)
   has history:          yes
   has statistics:       yes
   keyboard
     present:             yes
     rechargeable:        yes
     state:               discharging
     warning-level:       critical
     percentage:          1%
     icon-name:          'battery-caution-symbolic'

Re: Stylus battery reported as having 1% charge even though fully charged

[Bastien Nocera]

On Tue, 2022-07-19 at 11:38 +0200, Sebastian Arnhold wrote:
> Dear developers,
> 
> when using GNOME 42.3 on Wayland on my ASUS ExpertBook B5 Flip, it 
> reports my stylus battery to be stuck at 1% all the time, independent
> of 
> its actual charging status. This is also independent from the stylus
> I 
> use, as I've tried with two different ones.
> 
> The battery device registers as ELAN9008:00 04F3:2E12 in GNOME energy
> settings.
> 
> The GNOME developers helped me track the bug down to upower, as
> upower 
> itself shows the charging status to be stuck at 1%. The upower 
> developers then sent me here.
> 
> My kernel version is 5.18 on an x86_64 architecture on Fedora 36. My 
> upower version is 0.99.19.
> 
> Observed behaviour: Kernel reports 1% after pen is switched on and 
> touches the touchscreen for the first time. upower reports this to
> GNOME 
> which then throws a "Battery low"-warning message.
> Expected behaviour: Kernel reporting the correct charging percentage 
> from the pen to upower, or 0% if charging status cannot be
> determined. 
> The latter would be a workaround since 0% seems to be ignored by
> GNOME.
> 
> Can you help me to resolve this bug?

You'll probably want to implement a patch similar to this one:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f3193ea1b6779023334faa72b214ece457e02656

Cheers

Re: Stylus battery reported as having 1% charge even though fully charged

[Sebastian Arnhold]

Sadly, I'm not a programmer. Anyways, I wanted to report it - and would 
be very thankful if this bug could be fixed in one of the next kernel 
releases. :) Thanks in advance, Sebastian

Am 21.07.22 um 10:53 schrieb Bastien Nocera:
> On Tue, 2022-07-19 at 11:38 +0200, Sebastian Arnhold wrote:
>> Dear developers,
>>
>> when using GNOME 42.3 on Wayland on my ASUS ExpertBook B5 Flip, it
>> reports my stylus battery to be stuck at 1% all the time, independent
>> of
>> its actual charging status. This is also independent from the stylus
>> I
>> use, as I've tried with two different ones.
>>
>> The battery device registers as ELAN9008:00 04F3:2E12 in GNOME energy
>> settings.
>>
>> The GNOME developers helped me track the bug down to upower, as
>> upower
>> itself shows the charging status to be stuck at 1%. The upower
>> developers then sent me here.
>>
>> My kernel version is 5.18 on an x86_64 architecture on Fedora 36. My
>> upower version is 0.99.19.
>>
>> Observed behaviour: Kernel reports 1% after pen is switched on and
>> touches the touchscreen for the first time. upower reports this to
>> GNOME
>> which then throws a "Battery low"-warning message.
>> Expected behaviour: Kernel reporting the correct charging percentage
>> from the pen to upower, or 0% if charging status cannot be
>> determined.
>> The latter would be a workaround since 0% seems to be ignored by
>> GNOME.
>>
>> Can you help me to resolve this bug?
> You'll probably want to implement a patch similar to this one:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f3193ea1b6779023334faa72b214ece457e02656
>
> Cheers

Re: Stylus battery reported as having 1% charge even though fully charged

[Gregor Riepl]

> You'll probably want to implement a patch similar to this one:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f3193ea1b6779023334faa72b214ece457e02656

Does this mean that the driver doesn't support battery status reporting
for some devices, or is the feature simply missing in this controller?